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/*
* Image output functions
*
* Copyright (C) 2019 Patrick McDermott
*
* This file is part of fbcon2png.
*
* fbcon2png is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* fbcon2png is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with fbcon2png. If not, see <http://www.gnu.org/licenses/>.
*/
#include "image.h"
#include <stdlib.h>
#include <stdio.h>
#include <png.h>
#include "i18n.h"
#include "text.h"
#define BIT_DEPTH 4
#define PALETTE_SIZE (1 << BIT_DEPTH)
#define PIXEL_SIZE ((BIT_DEPTH + 7) / 8)
struct image {
png_structp png_ptr;
png_infop info_ptr;
};
static png_color palette[PALETTE_SIZE];
struct image *
image_new(const char *file_name)
{
struct image *image;
FILE *fp;
image = calloc(1, sizeof(*image));
if (!image) {
return NULL;
}
fp = fopen(file_name, "wb");
if (!fp) {
printf(_("Error: Cannot open \"%s\" for writing\n"), file_name);
return image_destroy(&image);
}
image->png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL);
if (!image->png_ptr) {
return image_destroy(&image);
}
image->info_ptr = png_create_info_struct(image->png_ptr);
if (!image->info_ptr) {
return image_destroy(&image);
}
png_init_io(image->png_ptr, fp);
return image;
}
void
image_render(struct image *image, struct text *text)
{
size_t width;
size_t height;
png_bytepp rows;
size_t i;
width = text_get_width(text);
height = text_get_height(text);
png_set_IHDR(image->png_ptr, image->info_ptr, width, height,
BIT_DEPTH, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_PLTE(image->png_ptr, image->info_ptr, palette, PALETTE_SIZE);
rows = png_malloc(image->png_ptr, height * sizeof(*rows));
for (i = 0; i < height; ++i) {
rows[i] = png_malloc(image->png_ptr, width * PIXEL_SIZE);
}
png_set_rows(image->png_ptr, image->info_ptr, rows);
png_write_png(image->png_ptr, image->info_ptr, PNG_TRANSFORM_IDENTITY,
NULL);
for (i = 0; i < height; ++i) {
png_free(image->png_ptr, rows[i]);
}
png_free(image->png_ptr, rows);
}
struct image *
image_destroy(struct image **image_p)
{
struct image *image;
image = *image_p;
png_destroy_write_struct(&image->png_ptr, &image->info_ptr);
free(image);
return image = NULL;
}
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